Comments on the proposed conservation of usage of Drosophila Fallén, 1823 (Insecta, Diptera) 5 (Case 3407)

Publication Type:Journal Article
Year of Publication:2008
Authors:S. D. Gaimari
Journal:Bulletin of Zoological Nomenclature
Start Page:146
Date Published:06/2008
Type of Article:Comment
Full Text

The application to set aside all previous type fixations for the genus DrosophilaFallén, 1823 and to instead fix Drosophila melanogaster (Meigen, 1830) as the type species should be rejected for several reasons:
  1. The authors incorrectly state that the application falls under Article 70.2 of the Code, which specifically refers to situations of overlooked type fixation (i.e., if an earlier type fixation had been overlooked, it would still be the valid type fixation with all subsequent type fixations invalid; but if this would cause instability or confusion, the case would need to be referred to the Commission). Nothing in the current application falls under the provisions of this Article, as there has been no overlooked type fixation. For Drosophila, type fixation and details of that fixation have been published numerous times in catalogues (Wheeler, 1965, 1970; Okada, 1977; Tsacas, 1980; Bächli & Rocha Pité, 1984; Evenhuis & Okada, 1989), major revisions (Sturtevant, 1942; Patterson, 1943; Hardy, 1965; Wheeler, 1981; Grimaldi, 1990), and other works (e.g. Sabrosky, 1999) since Musca funebris Fabricius, 1787 was fixed as the type species by Macquart (1835). There were many incorrect attributions of this same type fixation to Zetterstedt (1847), but it is evident in Zetterstedt (1847, see p. 2563) that he was following Macquart’s (1835) type species designation. The details of the erroneous type fixation of Musca cellaris Linnaeus, 1758 are clear, as the species was not eligible (see Sabrosky, 1999, p. 118). In a nomenclatural sense, there is nothing confusing or unstable about the type fixation for eitherDrosophila or Sophophora Sturtevant, 1939.
  2. Even if the valid and non-controversial type fixation by Macquart (1835) was to be set aside, for whatever reason, Article 67.2 expressly states that the only species eligible for this fixation are the originally included nominal species in Fallén (1823), which are listed in the application. Drosophila melanogaster is not eligible, as it was not originally included, and was not even described until seven years later.
  3. Stability is not achieved through the proposed application. In fact, quite the opposite, as there will be tremendous instability created in the rest of Drosophila. The authors state that Drosophila (with the type being Musca funebris) andSophophora (with the type being Drosophila melanogaster) will be in different genera as a result of their phylogenetic studies. So, setting aside Musca funebrisin deference to Drosophila melanogaster will result in many hundreds of species being displaced from Drosophila. This will be a far greater source of instability than that achieved by conserving the combination of a single species.
  4. This seems to be a perfect example of an attempt to change nomenclature to fit current taxonomic and phylogenetic thought, when in fact this is not a nomenclatural issue at all. The defining principles of nomenclature are entirely independent of scientific opinions of relationships among taxa.
  The underlying principles of nomenclature (see the Code’s Principles on pp. XIX–XX) should not be disregarded for the convenience of maintaining the taxonomic combination of a single species. The effect of a change in the type species ofDrosophila for the sake of this single species would potentially cause confusion and severe instability with regards to all previous works that had used Drosophilain the context of its validly designated and recognized type species, Musca funebris (also a very common, well known, near cosmopolitan species). The resulting objective synonymy of Sophophora under Drosophila would leave the taxonomic definition of Drosophila (in the sense of Drosophila funebris) unstable, with hundreds of species left in limbo. There can be no justification for changing a type species simply to support the results of the most recent phylogenetic study, as this is an entirely different matter from nomenclature. The singular popularity of a species, or the most current phylogenetic hypothesis of its relationships, cannot be deemed reason to force nomenclature to follow it. As science progresses, and more species become critical model organisms, or become better known in a phylogenetic sense, the Code cannot be expected to jump with each new phylogenetic hypothesis. Stability is measured in centuries, not in what is currently in fashion.

Additional references

Bächli, G. & Rocha Pité, M.T. 1984. Family Drosophilidae. Pp. 186–220 inPapp, L. & Soós, Á. (Eds.), Catalogue of Palaearctic Diptera. Volume 10. Clusiidae – Chloropidae. 402 pp. Akadémiae Kiadó, Budapest.
Evenhuis, N.L. & Okada, T. 1989. 98. Family Drosophilidae. Pp. 609–638 inEvenhuis, N.L. (Ed.), Catalog of the Diptera of the Australasian and Oceanian Regions. Bishop Museum Special Publication no. 86. 1155 pp. E.J. Brill & Bishop Museum Press, Honolulu.
Grimaldi, D.A. 1990. A phylogenetic, revised classification of genera in the Drosophilidae (Diptera). Bulletin of the American Museum of Natural History,197: 1–139.
Hardy, D.E. 1965. Diptera: Cyclorrhapha II, Series Schizophora, Section Acalypterae I, Family Drosophilidae. Insects of Hawaii12: 1–814.
Okada, T. 1977. Family Drosophilidae. Pp. 342–387 in Delfinado, M.D. & Hardy, D.E. (Eds.), A catalog of the Diptera of the Oriental Region. Vol. III. Suborder Cyclorrhapha (excluding Division Aschiza). 854 pp. The University Press of Hawaii, Honolulu.
Patterson, J.T. 1943. Studies in the genetics of Drosophila. III. The Drosophilidae of the Southwest. University of Texas Publication4313: 1–327.
Sabrosky, C.W. 1999. Family-group names in Diptera. An annotated catalog.Myia10: 576 pp. Backhuys, Leiden.
Tsacas, L. 1980. 74. Family Drosophilidae. Pp. 673–685 in Crosskey, R.W. (ed.),Catalogue of the Diptera of the Afrotropical Region. 1437 pp. British Museum (Natural History): London.
Wheeler, M.R. 1965. Family Drosophilidae. Pp. 760–772 in Stone, A., Sabrosky, C.W., Wirth, W.W., Foote, R.H. & Coulson, J.R. (Eds.), A catalog of the Diptera of America north of Mexico. 1696 pp. United States Department of Agriculture, Agriculture Handbook no. 276.
Wheeler, M.R. 1970. 79. Family Drosophilidae. A Catalogue of the Diptera of the Americas south of the United States79: 1–65.
Wheeler, M.R. 1981. The Drosophilidae: A taxonomic overview. Pp. 1–97 inAshburner, M., Carson, H.L., & Thompson, J.N., Jr. (Eds.), The genetics and biology of Drosophila. Vol. 3a. lxx, 429 pp. Academic Press, London.

Taxonomic Group(s): 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith